The Schlieffen Plan

Model answer

First, the forts around Liège held out until 16 August, so the Germans had to bring up enormous siege howitzers to smash them before their armies could pass through. Second, the Belgians destroyed railway lines, bridges and tunnels, which slowed down German troops and supplies and meant the invaders had to march further on foot.

Model answer

Source A is critical of the advance because the soldier describes an army worn out by its own speed. He says they have marched 'often 40 kilometres a day, in heat and dust', that their boots are 'worn through' and that the field kitchens 'hardly ever catch up'. The horses are 'dropping by the roadside'. He also shows that the men no longer trust their officers: they are told Paris is near, but 'nobody believes it any more', and the French, supposedly beaten, keep turning to fight.

This matches what we know. The Schlieffen Plan demanded that the German right wing, especially von Kluck's First Army on the outside of the wheel, march hundreds of kilometres through Belgium and France in a few weeks. The Belgians had destroyed railways and bridges, so supplies had to be brought forward by horse and cart, and they fell further and further behind. The French and British had retreated in good order, fighting battles such as Mons and Le Cateau. The letter is dated 4 September 1914, just before the Allied counter-attack at the Marne forced the exhausted Germans to retreat. As a private letter to his parents, it may be more honest than official reports.

Model answer

Source B is useful because it shows how much the Schlieffen Plan depended on passing through Belgium. Germany asked Belgium to let its troops through and gave it only twelve hours to reply, which reflects the tight timetable of a plan that aimed to defeat France in about six weeks before Russia was ready. The promise to respect Belgian independence and pay for damage, together with the threat to treat Belgium as an enemy, shows that Germany hoped to get through without a fight. The provenance makes it valuable as evidence of German aims, since it is the official note itself. However, it must be treated with care: its claim that French forces intended to march through Belgium was false. France's war plan, Plan XVII, was aimed at Alsace-Lorraine, and French troops had orders not to enter Belgium first. The note's claim was an excuse to justify breaking Belgian neutrality.

Source C is useful because it shows Belgium's decision to resist. The Belgian government says accepting would 'sacrifice the honour of the nation' and that it is 'firmly resolved to repel' any attack. This decision had major effects on the plan. When German troops invaded on 4 August, the forts around Liège held out until 16 August, forcing the Germans to bring up huge siege howitzers, and the Belgians blew up railways and bridges. Belgium's appeal to its 'duties towards Europe' also points to the Treaty of London of 1839, which led Britain to declare war on 4 August and send the BEF, which met the Germans at Mons on 23 August. As an official reply, it is reliable about Belgium's position, though it is also a public statement written to win the sympathy of the great powers.

Overall, the sources are useful together because they explain why the invasion became a problem: Germany needed a quick passage, and Belgium refused. Their main limitation is that both were written before the fighting began, so they show intentions rather than effects. An historian would need other evidence, such as accounts of the siege of Liège or of the BEF's arrival, to judge how much the invasion actually delayed the Germans.

Model answer

The Schlieffen Plan was designed to avoid a war on two fronts by defeating France before Russia could mobilise. Russia's speed undermined one of its central assumptions, and this had important consequences, but I do not think it was the main reason the plan failed, because the failure happened in the west, at the Battle of the Marne.

Russia's speed was certainly significant. Schlieffen had assumed that Russia, with its huge size and poor railways, would take about six weeks to mobilise. But Russia ordered general mobilisation on 30 July 1914, its railways had been improved with French loans, and two Russian armies under Rennenkampf and Samsonov invaded East Prussia from about 17 August, little more than two weeks into the war. The German Eighth Army was pushed back at Gumbinnen, and its commander talked of abandoning East Prussia. This caused alarm in Germany, and around 25-26 August Moltke took two army corps from the right wing in Belgium and sent them east. These men were badly missed in the west when, at the Marne, a gap opened between the German First and Second Armies. In this way, Russia's speed weakened the right wing at the crucial moment.

However, there are strong reasons to doubt that this was the main reason. The two corps arrived in the east too late to take part in the Battle of Tannenberg, where Hindenburg and Ludendorff destroyed Samsonov's army between 26 and 30 August without them. The east was therefore secure, and the real damage came from Moltke's decision rather than from the Russian advance itself. In addition, the right wing had already been weakened before the war, when Moltke changed Schlieffen's balance from seven to one to about three to one.

Other factors were more important. Belgian resistance at Liège, which held out until 16 August, and the destruction of Belgian railways slowed the German advance. Britain entered the war because of the invasion of Belgium, and the BEF delayed the Germans at Mons and Le Cateau. Above all, the French recovered. Joffre kept his armies intact during the retreat, moved troops west by rail and created a new Sixth Army near Paris. When von Kluck turned east of Paris and exposed his flank, the French attacked on 6 September, and the BEF and French Fifth Army advanced into the gap. The German armies, exhausted after weeks of marching and with stretched supply lines, retreated to the Aisne.

In conclusion, Russia's speed was an important factor because it proved one of Schlieffen's key assumptions wrong and led Moltke to weaken the right wing. But the plan failed in the west, where the French counter-attack at the Marne, made possible by Joffre's redeployment and German mistakes, was decisive. Russia's speed contributed to the failure, but it was not the main reason.